1. Technical Field
The present invention relates to an image display apparatus having an attitude detection function, and an electronic apparatus having the same.
2. Description of the Related Art
In the related art, there has been a technology of providing an optical sensor, and a light shielding body that selectively blocks a light incident into the optical sensor in response to an attitude with respect to the direction of gravitational force, and detecting the attitude of an apparatus based on the received amount of the light incident into the optical sensor.
For example, Japanese Unexamined Patent Application Publication No. 2007-147557 discloses an angle detecting sensor including a base, a casing, a light receiving element and a light shielding body. The light receiving element is prepared at the base, and the light shielding body with adjustable displacement is supported by a cylindrical inner wall support surface of the casing so as to shield the light receiving element. The light receiving element has a circular acceptance region, and the acceptance region includes four acceptance planes obtained by quadrisecting the area. According to the tilting of the angle detecting sensor, the light-shielding body is displaced by the gravity. If the light-shielding body is displaced, the amount of a light received on each acceptance plane also varies and each acceptance plane outputs analog signals corresponding to each amount of the light received. The analog signals output from each acceptance plane are processed by a signal processing circuit, so that tilting angles of the angle detecting sensor is detected. Thus, the angle detecting sensor can detect tilting angles correctly and stably, even under the conditions where the angle detecting sensor repeats attitude variations, while attempting reduction in size and weight.